1. Field of the Invention
The present invention relates to a power amplifier which is used for a mobile phone etc.
2. Background Art
Since power amplifiers occupy a large weight in the power consumption of mobile phones, making power amplifiers highly efficient is important for reducing power consumption. Therefore, power amplifiers for switching a high-power mode and a low-power mode using a switch have been used (for example, refer to Japanese Patent Application Laid-Open No. 7-336168).